
Light and color 23
FIGURE 1.13: Left: (u
0
, v
0
) chromaticity coordinates, from [11]. Right: (x, y)
chromaticity coordinates from the CIE 1931 xy chromaticity diagram. Figure
from [13].
FIGURE 1.14: CIELAB color space in both Cartesian and cylindrical coor-
dinates.
1.4.3 Limitations of CIELUV and CIELAB
We mentioned that in the CIE xy diagram, Euclidean distances between
chromaticities do not correspond to perceptual differences between colors,
e.g. the mixture of two colors in the same proportion should be located at
the midpoint of the segment determined by these colors in the diagram, but